Dual cooling airflow to blades

ABSTRACT

An airfoil may comprise a root and an airfoil body radially outward of the root. The airfoil body may define a first cooling chamber and a second cooling chamber. A first passage may be defined within the root and configured to direct a first airflow radially outward through the root into the first cooling chamber. A second passage may be defined within the root and configured to direct a second airflow radially outward through the root and into the second cooling chamber.

FIELD

The present disclosure relates to cooling systems for gas turbineengines, and more specifically, to blade cooling systems.

BACKGROUND

A gas turbine engine typically includes a fan section, a compressorsection, a combustor section, and a turbine section. A fan section maydrive air along a bypass flow path while a compressor section may driveair along a core flow path. In general, during operation, air ispressurized in the compressor section and is mixed with fuel and burnedin the combustor section to generate hot combustion gases. The hotcombustion gases flow through the turbine section, which extracts energyfrom the hot combustion gases to power the compressor section and othergas turbine engine loads. The compressor section typically includes lowpressure and high pressure compressors, and the turbine section includeslow pressure and high pressure turbines. The turbine section includesmultiple stages of blades and vanes. As fluid flows through the turbinesection, the flow causes the blades to rotate about an axis of rotation.The vanes, positioned between each row of blades, are used to redirectthe flow in order to maximize the power received by the downstreamblades.

Temperatures within the turbine section may be relatively high, as theflow of fluid is received initially from the combustor section of thegas turbine engine. Cooling air may be extracted from the compressorsection and used to cool the gas path components. Cooled components mayinclude, for example, rotating blades and stator vanes in the turbinesection.

SUMMARY

An airfoil for a gas turbine engine is provided. The airfoil may includea root and an airfoil body radially outward of the root. The airfoilbody may define a first cooling chamber and a second cooling chamber. Afirst passage may be defined within the root and configured to direct afirst airflow radially outward through the root into the first coolingchamber. A second passage may be defined within the root and configuredto direct a second airflow radially outward through the root and intothe second cooling chamber.

In various embodiments, a first inlet may be defined in an axiallyforward surface of the root. A second inlet may be defined in an axiallyaft surface of the root. The airfoil may further comprise a leading edgeand a trailing edge. The first cooling chamber may be disposed at theleading edge and the second cooling chamber may be disposed at thetrailing edge. The airfoil body may define a first plurality of holes atthe leading edge. The first airflow may be directed out the airfoilthrough the first plurality of holes. The airfoil body may define asecond plurality of holes at the trailing edge. The second airflow maybe directed out the airfoil through the second plurality of holes. Theairfoil may comprise a blade.

An engine section of a gas turbine engine is also provided. The enginesection may comprise a disk configured to rotate about an axis and ablade coupled to the disk. The blade may define a first cooling chamberand a second cooling chamber. A first flow guide may be disposedupstream of the disk. The first flow guide may define a first airflowpath and a second airflow path. A first passage may be configured todirect the first airflow path to the first cooling chamber. A secondpassage may be configured to direct the second airflow path to thesecond cooling chamber.

In various embodiments, a first tangential onboard injector (TOBI) maybe disposed in the first airflow path. The first passage may include afirst inlet defined in an axially forward surface of the disk. The firstTOBI may be configured to direct the first airflow path into the firstinlet. A second TOBI may be disposed in the second airflow path. Thesecond passage may include a second inlet defined in the axially forwardsurface of the disk. The second TOBI may be configured to direct thesecond airflow path into the second inlet. The first passage may includea first inlet defined in an axially forward surface of a root. Thesecond passage may include a second inlet defined in the axially forwardsurface of the disk. A radial onboard injector (ROBI) may be disposed inthe second airflow path forward of the disk and configured to direct thesecond airflow path radially inward. A minidisk may be coupled to anaxially aft surface of the disk. The second airflow may be directedradially outward between the minidisk and the axially aft surface of thedisk. The blade may define a first plurality of holes at a leading edge.The first airflow may be directed out the blade through the firstplurality of holes.

A gas turbine engine may comprise a compressor section configured tosupply airflow to at least one of a first airflow path or a secondairflow path. A turbine section may be configured to receive airflowfrom the first airflow path and the second airflow path. The turbinesection may comprise a disk configured to rotate about an axis and ablade coupled to the disk. The blade may define a first cooling chamberand a second cooling chamber. A first passage may be configured todirect a first airflow path to the first cooling chamber. A secondpassage may be configured direct the second airflow path to the secondcooling chamber.

In various embodiments, a first flow guide may be disposed upstream ofthe disk. The first flow guide may define the first airflow path and thesecond airflow path. A first TOBI may be disposed in the first airflowpath. The first passage may include a first inlet defined in an axiallyforward surface of the disk. The first TOBI may be configured to directthe first airflow path into the first inlet. A second TOBI may bedisposed in the second airflow path. The second passage may include asecond inlet defined in the axially forward surface of the disk. Thesecond TOBI may be configured to direct the second airflow path into thesecond inlet. A ROBI may be disposed in the second airflow path forwardof the disk and configured to direct the second airflow path radiallyinward. A minidisk may be coupled to an axially aft surface of the disk.The second airflow path may be directed radially outward between theminidisk and the axially aft surface of the disk.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. It should be understood, however, the following descriptionand drawings are intended to be exemplary in nature and non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the detailed description and claims whenconsidered in connection with the figures, wherein like numerals denotelike elements.

FIG. 1 illustrates a cross-sectional view of an exemplary gas turbineengine, in accordance with various embodiments;

FIG. 2 illustrates a cross-sectional view of an engine section of gasturbine engine, according to various embodiments;

FIGS. 3A and 3B illustrate cross-sectional views of a cooling system foran airfoil, in accordance with various embodiments;

FIG. 4 illustrates a cross-sectional view of a cooling system for anairfoil, in accordance with various embodiments;

FIG. 5 illustrates a cross-sectional view of a cooling system for anairfoil, in accordance with various embodiments; and

FIG. 6 illustrates a cross-sectional view of a cooling system for anairfoil, in accordance with various embodiments.

DETAILED DESCRIPTION

All ranges and ratio limits disclosed herein may be combined. It is tobe understood that unless specifically stated otherwise, references to“a,” “an,” and/or “the” may include one or more than one and thatreference to an item in the singular may also include the item in theplural.

The detailed description of various embodiments herein makes referenceto the accompanying drawings, which show various embodiments by way ofillustration. While these various embodiments are described insufficient detail to enable those skilled in the art to practice thedisclosure, it should be understood that other embodiments may berealized and that logical, chemical, and mechanical changes may be madewithout departing from the spirit and scope of the disclosure. Thus, thedetailed description herein is presented for purposes of illustrationonly and not of limitation. For example, the steps recited in any of themethod or process descriptions may be executed in any order and are notnecessarily limited to the order presented. Furthermore, any referenceto singular includes plural embodiments, and any reference to more thanone component or step may include a singular embodiment or step. Also,any reference to attached, fixed, connected, or the like may includepermanent, removable, temporary, partial, full, and/or any otherpossible attachment option. Any reference related to fluidic coupling toserve as a conduit for cooling airflow and the like may includepermanent, removable, temporary, partial, full, and/or any otherpossible attachment option. Additionally, any reference to withoutcontact (or similar phrases) may also include reduced contact or minimalcontact. Cross hatching lines may be used throughout the figures todenote different parts but not necessarily to denote the same ordifferent materials.

As used herein, “aft” refers to the direction associated with theexhaust (e.g., the back end) of a gas turbine engine. As used herein,“forward” refers to the direction associated with the intake (e.g., thefront end) of a gas turbine engine.

A first component that is “radially outward” of a second component meansthat the first component is positioned at a greater distance away fromthe engine central longitudinal axis than the second component. A firstcomponent that is “radially inward” of a second component means that thefirst component is positioned closer to the engine central longitudinalaxis than the second component. In the case of components that rotatecircumferentially about the engine central longitudinal axis, a firstcomponent that is radially inward of a second component rotates througha circumferentially shorter path than the second component. Theterminology “radially outward” and “radially inward” may also be usedrelative to references other than the engine central longitudinal axis.A first component that is “radially outward” of a second component meansthat the first component is positioned at a greater distance away fromthe engine central longitudinal axis than the second component. As usedherein, “distal” refers to the direction outward, or generally, awayfrom a reference component. As used herein, “proximal” refers to adirection inward, or generally, towards the reference component.

The next generation turbofan engines are designed for higher efficiencyand use higher pressure ratios and higher temperatures in the highpressure compressor than are conventionally experienced. These higheroperating temperatures and pressure ratios create operating environmentsthat cause thermal loads that are higher than the thermal loadsconventionally experienced, which may shorten the operational life ofcurrent components.

Blades may include a cooling system, which may direct multiple airflowpaths through the body of the blade. A first airflow may be directedinto the blade through a disk and may exit the blade through leadingedge cooling holes. A second airflow may be directed into the bladethrough the disk and may exit the blade through trailing edge coolingholes. The first airflow and second airflow may be sourced fromdifferent locations in the engine, and may have different temperaturesor pressures. One or more flow guides, seals, injectors, and/or flowbaffles may be employed to direct the first and second flow paths intothe blade.

With reference to FIG. 1, a gas turbine engine 20 is shown according tovarious embodiments. Gas turbine engine 20 may be a two-spool turbofanthat generally incorporates a fan section 22, a compressor section 24, acombustor section 26 and a turbine section 28. Alternative engines mayinclude, for example, an augmentor section among other systems orfeatures. In operation, fan section 22 can drive coolant (e.g., air)along a path of bypass airflow B while compressor section 24 can drivecoolant along a core flow path C for compression and communication intocombustor section 26 then expansion through turbine section 28. Althoughdepicted as a turbofan gas turbine engine 20 herein, it should beunderstood that the concepts described herein are not limited to usewith turbofans as the teachings may be applied to other types of turbineengines including three-spool architectures.

Gas turbine engine 20 may generally comprise a low speed spool 30 and ahigh speed spool 32 mounted for rotation about an engine centrallongitudinal axis A-A′ relative to an engine static structure 36 orengine case via several bearing systems 38, 38-1, and 38-2. Enginecentral longitudinal axis A-A′ is oriented in the z direction on theprovided x-y-z axes. It should be understood that various bearingsystems 38 at various locations may alternatively or additionally beprovided, including for example, bearing system 38, bearing system 38-1,and bearing system 38-2.

Low speed spool 30 may generally comprise an inner shaft 40 thatinterconnects a fan 42, a low pressure compressor 44 and a low pressureturbine 46. Inner shaft 40 may be connected to fan 42 through a gearedarchitecture 48 that can drive fan 42 at a lower speed than low speedspool 30. Geared architecture 48 may comprise a gear assembly 60enclosed within a gear housing 62. Gear assembly 60 couples inner shaft40 to a rotating fan structure. High speed spool 32 may comprise anouter shaft 50 that interconnects a high pressure compressor 52 and highpressure turbine 54. A combustor 56 may be located between high pressurecompressor 52 and high pressure turbine 54. A mid-turbine frame 57 ofengine static structure 36 may be located generally between highpressure turbine 54 and low pressure turbine 46. Mid-turbine frame 57may support one or more bearing systems 38 in turbine section 28. Innershaft 40 and outer shaft 50 may be concentric and rotate via bearingsystems 38 about the engine central longitudinal axis A-A′, which iscollinear with their longitudinal axes. As used herein, a “highpressure” compressor or turbine experiences a higher pressure than acorresponding “low pressure” compressor or turbine.

The core airflow may be compressed by low pressure compressor 44 thenhigh pressure compressor 52, mixed and burned with fuel in combustor 56,then expanded over high pressure turbine 54 and low pressure turbine 46.Turbines 46, 54 rotationally drive the respective low speed spool 30 andhigh speed spool 32 in response to the expansion.

Gas turbine engine 20 may be, for example, a high-bypass ratio gearedaircraft engine. In various embodiments, the bypass ratio of gas turbineengine 20 may be greater than about six (6). In various embodiments, thebypass ratio of gas turbine engine 20 may be greater than ten (10). Invarious embodiments, geared architecture 48 may be an epicyclic geartrain, such as a star gear system (sun gear in meshing engagement with aplurality of star gears supported by a carrier and in meshing engagementwith a ring gear) or other gear system. Geared architecture 48 may havea gear reduction ratio of greater than about 2.3 and low pressureturbine 46 may have a pressure ratio that is greater than about five(5). In various embodiments, the bypass ratio of gas turbine engine 20is greater than about ten (10:1). In various embodiments, the diameterof fan 42 may be significantly larger than that of the low pressurecompressor 44, and the low pressure turbine 46 may have a pressure ratiothat is greater than about five (5:1). Low pressure turbine 46 pressureratio may be measured prior to inlet of low pressure turbine 46 asrelated to the pressure at the outlet of low pressure turbine 46 priorto an exhaust nozzle. It should be understood, however, that the aboveparameters are exemplary of various embodiments of a suitable gearedarchitecture engine and that the present disclosure contemplates othergas turbine engines including direct drive turbofans. A gas turbineengine may comprise an industrial gas turbine (IGT) or a geared aircraftengine, such as a geared turbofan, or non-geared aircraft engine, suchas a turbofan, or may comprise any gas turbine engine as desired.

Referring now to FIG. 2 and still to FIG. 1, according to variousembodiments, each of low pressure compressor 44, high pressurecompressor 52, low pressure turbine 46, and high pressure turbine 54 ingas turbine engine 20 may comprise one or more stages or sets ofrotating blades and one or more stages or sets of stationary vanesaxially interspersed with the associated blade stages but non-rotatingabout engine central longitudinal axis A-A′. The compressor and turbinesections 24, 28 may be referred to as rotor assemblies 110. Eachcompressor stage and turbine stage may comprise multiple interspersedstages of blades 101 and vanes 102. Within the rotor assemblies 110 ofgas turbine engine 20 are multiple rotor disks, which may include one ormore cover plates or minidisks. The blades 101 rotate about enginecentral longitudinal axis A-A′, while the vanes 102 remain stationarywith respect to engine central longitudinal axis A-A′. For example, FIG.2 schematically shows, by example, a portion of an engine section 80,which is illustrated as a turbine section 28 of gas turbine engine 20.It will be understood that the cooling systems in the present disclosureare not limited to the turbine section, and could extend to othersections of the gas turbine engine 20, including but not limited tocompressor section 24.

Engine section 80 may include alternating rows of blades 101 and vanes102 comprising airfoils that extend into the core flow path C. Vanes 102may be arranged circumferentially about engine central longitudinal axisA-A′. Vanes 102 direct the core airflow to blades 101 to either add orextract energy. Blades 101 create or extract energy from the coreairflow that is communicated through engine section 80 along the coreflow path C. In various embodiments, a set of blades 104 may be coupledabout a circumference of a generally circular disk 104, which may bedisposed radially inward of core flow path C. Disk 104 with blades 101may be configured to rotate about engine central longitudinal axis A-A′.Disk 104 and blade 101 may comprise a rotor assembly 110 of enginesection 80. Each blade 101 may include an attachment or root 106disposed at an inner diameter 108 of an airfoil body 109. For example,the airfoil body 109 may extend radially outward from the root 106.

Engine section 80 may include a plurality of rotor assemblies 110 withone or more of the rotor assemblies 110 further including one or morecover plates 112 or minidisks 114 coupled to a disk 104. In variousembodiments, a cover plate 112 or a minidisk 114 may be coupled to anaxial surface of disk 104. For example, a cover plate 112 may be coupledto an axially forward surface 120 of disk 104, and a minidisk 114 may becoupled to an axially aft surface 122 of disk 104. Blades 101 and vanes102 may generally be referred to as airfoils 100.

In various embodiments, an airfoil 100 may be an internally cooledcomponent of gas turbine engine 20. Each airfoil 100, illustrated asblade 101, has an airfoil body 109 having a leading edge 124 facing aforward direction in the gas turbine engine and a trailing edge 126facing an aft direction. Airfoil 100 may include a pressure side wall(i.e. having a generally concave surface) and a suction side wall (i.e.having a generally convex surface) joined together at the respectiveleading edge 124 and trailing edge 126. Airfoil 100 may be configured toaccommodate first cooling chamber 132 and second cooling chamber 134within an airfoil body 105 of airfoil 100.

In various embodiments and with reference to FIGS. 3A and 3B and stillto FIG. 2, a rotor assembly 110 may comprise a cooling system 130 havinga first airflow path E and a second airflow path F. Cooling system 130may be located in any suitable position within gas turbine engine 20. Invarious embodiments, cooling system 130 may be configured to providemultiple airflow paths to deliver cooling airflow to an airfoil 100.With brief reference to FIG. 1, the airflow may originate from anysuitable source in gas turbine engine 20. For example, the airflow maycomprise air received from a compressor section of gas turbine engine20.

Returning to FIGS. 3A and 3B, a first airflow may be directed alongfirst airflow path E to provide cooling air to a first portion, such asthe leading edge 124, of airfoil 100. A second airflow may be directedalong second flowpath F to provide cooling air to a second portion, suchas the trailing edge 126, of airfoil 100. Cooling system 130 may beconfigured to convectively remove heat from the airfoil 100 by thecooling airflow along first flowpath E and second flowpath F. The firstflowpath E may be defined in part by a flow guide 150, which may be aninner diffuser case, disposed radially inward of first flowpath E andupstream of disk 104. The first flowpath E may be defined by a flowguide 152, such that first flowpath E is defined between flow guide 150and flow guide 152. The second flowpath F may be defined in part by aflow guide 150 disposed radially outward of second flowpath F. Thesecond flowpath F may be defined by a radially inner flow guide 154,such that second flowpath F is defined between flow guide 150 andradially inner flow guide 154. First flowpath E and second flowpath Fmay flow generally axially toward the rotor assembly 110, or generally,toward airfoil 100.

First airflow path E may be directed through a nozzle to introduce aswirl or tangential velocity into the first airflow path E, which isdirected toward airfoil 100 of rotor assembly 110. In variousembodiments, cooling airflow may be directed through a tangentialonboard injector (TOBI), which may direct the cooling airflow towardrotating components, such as rotor assembly 110. A TOBI may comprise anairfoil, and/or the like, configured to rotate the cooling airflowcircumferentially before expelling the airflow towards rotor assembly110. A TOBI may be configured to spin an airflow to a velocity thatclosely matches and/or is substantially the same as the linear velocityof a rotating component (e.g., rotor assembly 110), thereby limiting thetemperature increase between the airflow path and the rotatingcomponent.

In that regard, the first airflow path E may be directed into a firstTOBI 160. First TOBI 160 may be configured to receive the airflow of thefirst airflow path E and expel the airflow towards cover plate 112, suchthat first airflow path E exiting first TOBI 160 has a tangentialvelocity component to the cooling airflow. Cover plate 112 may controlairflow to axially forward surface 120 of disk 104. Generally, firstairflow path E may enter disk 104 and flow radially outward through disk104, root 106, and into first cooling chamber 132 of airfoil body 109.

In various embodiments, second airflow path F may be directed through anozzle to introduce a swirl or tangential velocity into the secondairflow path F, which is directed toward airfoil 100 of rotor assembly110. Second airflow path F may be directed into a second TOBI 170.Second TOBI 170 may be configured to receive the airflow of secondairflow path F and expel the airflow towards cover plate 112. Secondairflow path F exiting second TOBI 170 may have a tangential velocitycomponent to the cooling airflow. Generally, second airflow path F mayenter disk 104 and flow radially outward through disk 104, root 106, andinto second cooling chamber 134 of airfoil body 109.

The first airflow path E and the second airflow path F may have similaror different temperatures and/or pressures. The first airflow path E mayhave a higher pressure than the second airflow path F.

In various embodiments, a seal 180 may be disposed forward of disk 104and between first airflow path E and second airflow path F. Seal 180 maybe configured to fluidly isolate first airflow path E and second airflowpath F. Seal 180 may be a non-contacting dynamic seal, a “W” seal (e.g.a seal having a “W”-shaped cross-section or that forms a “W” shape), abrush seal, a rope seal, a “C” seal (e.g. a seal having a “C”-shapedcross-section or that forms a “C” shape), a crush seal, a flap seal, afeather seal, a knife-edge seal, or other suitable seal. Seal 180 maycomprise a continuous annular ring or may have at least onecircumferential split.

Turning to FIG. 3B, first airflow path E may exit first TOBI 160 and mayflow axially aft toward disk 104. First airflow path E may flow througha first aperture 162 defined in cover plate 112. First airflow path Emay enter disk 104 through a passage 164 defined within disk 104. Aninlet 166 of passage 164 may be defined in axially forward surface 120of disk 104. First TOBI 160 may be configured to direct the firstairflow path E into the inlet 166. Passage 164 may extend axiallypartially or completely through disk 104 and may further define firstairflow path E through disk 104. Passage 164 may redirect the firstairflow path E from flowing in an axial direction, such as the positivez-direction, to flowing in a radial direction, such as the positivey-direction. In that regard, passage 164 may direct first airflow path Eradially outward toward airfoil 100 and into root 106. The first airflowpath E may enter first cooling chamber 132 of airfoil 100 through anaperture in root 106. First airflow path E may be directed throughairfoil 100 and may exit the leading edge 124 of airfoil 100 through aplurality of holes 190 defined in the leading edge 124 of airfoil 100.

The second airflow path F may exit second TOBI 170 and may flow axiallyaft toward disk 104. The second airflow path F may flow through a secondaperture 172 defined in cover plate 112. Second airflow path F may enterdisk 104 through a passage 174 defined within disk 104. An inlet 176 ofpassage 174 may be defined in axially forward surface 120 of disk 104.Second TOBI may be configured to direct the second airflow path F intothe second inlet 176. Passage 174 may extend axially partially orcompletely through disk 104 and may further define the second airflowpath F through disk 104. Passage 174 may redirect the second airflowpath F from flowing in an axial direction, such as the positivez-direction, to flowing in a radial direction, such as the positivey-direction. In that regard, passage 174 may direct second airflow pathF radially outward toward airfoil 100 and into root 106. The secondairflow path F may enter second cooling chamber 134 of airfoil 100through an aperture in root 106. Second airflow path F may be directedthrough airfoil 100 and may exit the trailing edge 126 of airfoil 100through a plurality of holes 192 defined in the trailing edge 126 ofairfoil 100.

In various embodiments, passage 164 and passage 174 may be formed asseparate passages or as a single passage separated by a baffle 194.Baffle 194 may be disposed within passage 164 and/or passage 174 tofluidly isolate the first airflow path E from the second airflow path F.Baffle 194 may be configured to extent axially and/or radially withindisk 104 and between first airflow path E and second airflow path F.

With reference to FIG. 4, a cooling system 200 defining a first airflowpath G and a second airflow path H is shown in accordance with variousembodiments. A first airflow may be directed along first airflow path Gto provide cooling air to a first portion, such as the leading edge 124,of airfoil 100. A second airflow may be directed along second airflowpath H to provide cooling air to a second portion, such as the trailingedge 126, of airfoil 100. The first airflow path G may be defined inpart by a flow guide 152 disposed radially inward of first airflow pathG and upstream of disk 104. The first airflow path G may be furtherdefined by a radially inner surface of combustor 56, such that firstairflow path G is defined between flow guide 152 and combustor 56. Thesecond airflow path H may be defined in part by a flow guide 150, whichmay be an inner diffuser case, and by flow guide 152 which may bedisposed radially outward of second airflow path H. Thus, the secondairflow path H may be defined between flow guide 150 and flow guide 152.First airflow path G and second airflow path H may flow generallyaxially toward airfoil 100.

First airflow path G may be directed through a nozzle to introduce aswirl or tangential velocity into the first airflow path G, which isdirected toward airfoil 100 of rotor assembly 110. In that regard, thefirst airflow path G may be directed into a first TOBI 202. First TOBI202 may be configured to receive the airflow of the first airflow path Gand expel the airflow towards airfoil 100, or more specifically, root106. Thus, the first airflow path G may be directed into root 106.Generally, first airflow path G may enter root 106 and flow radiallyoutward through root 106 and into first cooling chamber 132 of airfoilbody 109. A passage 210 may be formed in root 106. Passage 210 mayinclude a first inlet 212 defined in an axially forward surface of theroot 106. Passage 210 may redirect first airflow path G from flowing inan axial direction, such as the positive z-direction, to flowing in aradial direction, such as the positive y-direction. In that regard,passage 210 may direct first airflow path G radially outward throughroot 106 and into airfoil 100. First airflow path G may enter firstcooling chamber 132 of airfoil 100 through an aperture in root 106.First airflow path G may be directed through airfoil 100 and may exitthe leading edge 124 of airfoil 100 through a plurality of holes 190defined in the leading edge 124 of airfoil 100.

The second airflow path H may be directed into a second TOBI 220. Thesecond TOBI 220 may be configured to receive the airflow of secondairflow path H and expel the airflow towards cover plate 112. Generally,second airflow path H may enter disk 104 and flow radially outwardthrough disk 104, root 106, and into second cooling chamber 134 ofairfoil 100. The second airflow path H may exit second TOBI 220 and mayflow axially aft toward disk 104. The second airflow path H may flowthrough an aperture 214 defined in cover plate 112. Second airflow pathH may enter disk 104 through a passage 222 defined within disk 104. Aninlet 224 of passage 222 may be defined in axially forward surface 120of disk 104. Second TOBI 220 may be configured to direct the secondairflow path H into the inlet 224. Passage 222 may extend axiallypartially or completely through disk 104 and may further define secondairflow path H through disk 104. Passage 222 may redirect the secondairflow path H from flowing in an axial direction, such as the positivez-direction, to flowing in a radial direction, such as the positivey-direction. In that regard, passage 222 may direct second airflow pathH radially outward toward airfoil 100 and into root 106. The secondairflow path H may enter second cooling chamber 134 of airfoil 100through an aperture in root 106. Second airflow path H may be directedthrough airfoil 100 and may exit the trailing edge 126 of airfoil 100through a plurality of holes 192 defined in the trailing edge 126 ofairfoil 100.

In various embodiments, the first airflow path G and the second airflowpath H may have similar or different temperatures and/or pressures.First airflow path G may have a higher pressure than the second airflowpath H.

With reference to FIG. 5, a cooling system 250 defining a first airflowpath J and a second airflow path K is shown in accordance with variousembodiments. A first airflow may be directed along first airflow path Jto provide cooling air to a first portion of airfoil 100, such as theleading edge 124 of airfoil 100. First airflow path J may be defined inpart by a flow guide 150, which may be an inner diffuser case, disposedradially inward of first airflow path J. First airflow path J may bedefined by a flow guide 152, such that first airflow path J is definedbetween flow guide 150 and flow guide 152. First airflow path J may flowgenerally axially toward airfoil 100.

A second airflow may be directed along second airflow path K to providecooling air to a second portion of airfoil 100, such as the trailingedge 126 of airfoil 100. Generally, second airflow path K may bedirected axially aft, and radially inward around disk 104 and radiallyoutward along an axially aft surface 122 of disk 104. The second airflowpath K may be defined in part by a flow guide 150 disposed radiallyoutward of second airflow path K.

In various embodiments, first airflow path J may be directed through anozzle to introduce a swirl or tangential velocity into the firstairflow path F, which is directed toward airfoil 100 of rotor assembly110. In that regard, first airflow path J may be directed into a TOBI260. The TOBI 260 may be configured to receive the airflow of firstairflow path J and expel the airflow towards cover plate 112. Generally,first airflow path J may enter disk 104 and flow radially outwardthrough disk 104, root 106, and into first cooling chamber 132 ofairfoil 100. The first airflow path J may exit TOBI 260 and may flowaxially aft toward disk 104. First airflow path J may flow through anaperture 262 defined in cover plate 112. First airflow path J may enterdisk 104 through a first passage 264 defined within disk 104. An inlet266 of first passage 264 may be defined in axially forward surface 120of disk 104. TOBI 260 may be configured to direct the first airflow pathJ into the inlet 266. First passage 264 may direct first airflow path Jradially outward toward airfoil 100 and into root 106. The first airflowpath J may enter first cooling chamber 132 of airfoil 100 through anaperture in root 106. First airflow path J may be directed throughairfoil 100 and may exit the leading edge 124 of airfoil 100 through aplurality of holes 190 defined in the leading edge 124 of airfoil 100.

Second airflow path K may be directed through a nozzle, which mayfurther define or direct the second airflow path K. In variousembodiments, cooling airflow may be directed through a radial onboardinjector (ROBI). A ROBI may include a plurality of injector bladesbetween at least two walls and may direct the airflow. The secondairflow path K may be directed into a ROBI 270. ROBI 270 may disposed inthe second airflow path K forward of the disk 104 and configured todirect the second airflow path K radially inward. While radially inwardof disk 104, second airflow path K may flow axially aft along an innersurface 272 of disk 104, toward the axially aft surface 122 of disk 104.Second airflow path K may be directed radially outward between minidisk114 and the axially aft surface 122 of the disk 104. Second airflow pathK may enter disk 104 through a second passage 274 defined within disk104. An inlet 276 of second passage 274 may be defined in axially aftsurface 122 of disk 104. Second passage 274 may extend axially partiallyor completely through disk 104 and may further define second airflowpath K through disk 104. Second passage 274 may redirect the secondairflow path K from flowing in an axial direction, such as the negativez-direction, to flowing in a radial direction, such as the positivey-direction. In that regard, passage 274 may direct second airflow pathK radially outward toward airfoil 100 and into root 106. Second airflowpath K may enter second cooling chamber 134 of airfoil 100 through anaperture in root 106. Second airflow path K may be directed throughairfoil 100 and may exit the trailing edge 126 of airfoil 100 through aplurality of holes 192 defined in the trailing edge 126 of airfoil 100.

In various embodiments, first passage 264 and second passage 274 may beformed as separate passages or as a single passage separated by a baffle280. Baffle 280 may be disposed within first passage 264 and secondpassage 274 to fluidly isolate the first airflow path J from the secondairflow path K. In various embodiments, the airflow of first airflowpath J and the airflow of second airflow path K may have similar ordifferent temperatures and/or pressures. First airflow path J may have ahigher pressure than the second airflow path K.

With reference to FIG. 6, a cooling system 300 defining a first airflowpath L and a second airflow path M is shown in accordance with variousembodiments. A first airflow may be directed along first airflow path Lto provide cooling air to a first portion, such as the leading edge 124,of airfoil body 109. First airflow path L may flow generally axiallytoward airfoil 100 of rotor assembly 110. First airflow path L may bedefined in part by a flow guide 152 disposed radially inward of firstairflow path L and upstream of disk 104. First airflow path L may befurther defined by a radially inner surface of combustor 56, such thatfirst airflow path L is defined between flow guide 152 and combustor 56.

A second airflow may be directed along second airflow path M to providecooling air to a second portion, such as the trailing edge 126, ofairfoil body 109. Generally, second airflow path M may be directedaxially aft, and radially inward around disk 104 and radially outwardalong an axially aft surface 122 of disk 104. The second airflow path Mmay be defined in part by a flow guide 150 disposed radially outward ofsecond airflow path M.

In various embodiments, first airflow path L may be directed through anozzle to introduce a swirl or tangential velocity into the firstairflow path L, which is directed toward airfoil 100 of rotor assembly110. In that regard, the first airflow path L may be directed into aTOBI 302. TOBI 302 may be configured to receive the airflow of the firstairflow path L and expel the airflow towards airfoil 100, or morespecifically, root 106. Thus, the first airflow path L may be directedinto root 106. Generally, first airflow path L may enter root 106 andflow radially outward through root 106 and into first cooling chamber132 of airfoil body 109. A first passage 304 may be formed in root 106.First passage 304 may include an inlet 306 defined in an axially forwardsurface 310 of the root 106. First passage 304 may redirect firstairflow path L from flowing in an axial direction, such as the positivez-direction, to flowing in a radial direction, such as the positivey-direction. In that regard, first passage 304 may direct first airflowpath L radially outward through root 106 and into airfoil body 109.First airflow path L may enter first cooling chamber 132 of airfoil 100through an aperture in root 106. First airflow path L may be directedthrough airfoil 100 and may exit the leading edge 124 of airfoil 100through a plurality of holes 190 defined in the leading edge 124 ofairfoil body 109.

In various embodiments, second airflow path M may be directed through anozzle, which may further define or direct the second airflow path M. Inthat regard, the second airflow path M may be directed into a ROBI 320.ROBI 320 may disposed in the second airflow path M forward of the disk104 and configured to direct the second airflow path M radially inward.While radially inward of disk 104, second airflow path M may flowaxially aft along an inner surface 272 of disk 104, toward the axiallyaft surface 122 of disk 104. Second airflow path M may be directedradially outward between minidisk 114 and the axially aft surface 122 ofthe disk 104. Second airflow path M may be directed into root 106.Generally, second airflow path M may enter root 106 and flow radiallyoutward through root 106 and into second cooling chamber 134 of airfoilbody 109. A second passage 322 may be formed in root 106. Second passage322 may include an inlet 324 defined in an aft forward surface 330 ofthe root 106. Second passage 322 may direct second airflow path Mradially outward toward airfoil 100 and into root 106. Second airflowpath M may enter second cooling chamber 134 of airfoil 100 through anaperture in root 106. Second airflow path M may be directed throughairfoil 100 and may exit the trailing edge 126 of airfoil 100 through aplurality of holes 192 defined in the trailing edge 126 of airfoil 100.

In various embodiments, the airflow of first airflow path L and theairflow of second airflow path M may have similar or differenttemperatures and/or pressures. First airflow path L may have a higherpressure than the second airflow path M.

Benefits and other advantages have been described herein with regard tospecific embodiments. Furthermore, the connecting lines shown in thevarious figures contained herein are intended to represent exemplaryfunctional relationships and/or physical couplings between the variouselements. It should be noted that many alternative or additionalfunctional relationships or physical connections may be present in apractical system. However, the benefits, advantages, and any elementsthat may cause any benefit or advantage to occur or become morepronounced are not to be construed as critical, required, or essentialfeatures or elements of the disclosure. The scope of the disclosure isaccordingly to be limited by nothing other than the appended claims, inwhich reference to an element in the singular is not intended to mean“one and only one” unless explicitly so stated, but rather “one ormore.” Moreover, where a phrase similar to “at least one of A, B, or C”is used in the claims, it is intended that the phrase be interpreted tomean that A alone may be present in an embodiment, B alone may bepresent in an embodiment, C alone may be present in an embodiment, orthat any combination of the elements A, B and C may be present in asingle embodiment; for example, A and B, A and C, B and C, or A and Band C.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “various embodiments”, “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described. After reading the description, itwill be apparent to one skilled in the relevant art(s) how to implementthe disclosure in alternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element is intended to invoke 35 U.S.C. 112(f)unless the element is expressly recited using the phrase “means for.” Asused herein, the terms “comprises”, “comprising”, or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus.

What is claimed is:
 1. An airfoil, comprising: a root; an airfoil bodyradially outward of the root, the airfoil body defining a first coolingchamber and a second cooling chamber; a first passage defined within theroot and configured to direct a first airflow received from a firsttangential onboard injector (TOBI) radially outward through the rootinto the first cooling chamber; and a second passage defined within theroot and configured to direct a second airflow received from a secondTOBI radially outward through the root and into the second coolingchamber, wherein the first TOBI is disposed radially outward from thesecond TOBI, and the first cooling chamber is disposed forward from thesecond cooling chamber.
 2. The airfoil of claim 1, further comprising afirst inlet defined in an axially forward surface of the root.
 3. Theairfoil of claim 2, further comprising a second inlet defined in anaxially aft surface of the root.
 4. The airfoil of claim 3, furthercomprising a leading edge and a trailing edge, wherein the first coolingchamber is disposed at the leading edge and the second cooling chamberis disposed at the trailing edge.
 5. The airfoil of claim 4, wherein theairfoil body defines a first plurality of holes at the leading edge, andwherein the first airflow is directed out the airfoil through the firstplurality of holes.
 6. The airfoil of claim 5, wherein the airfoil bodydefines a second plurality of holes at the trailing edge, and whereinthe second airflow is directed out the airfoil through the secondplurality of holes.
 7. The airfoil of claim 1, wherein the airfoilcomprises a blade.
 8. An engine section of a gas turbine engine,comprising: a disk configured to rotate about an axis; a blade coupledto the disk, the blade defining a first cooling chamber and a secondcooling chamber; a first flow guide disposed upstream of the disk, thefirst flow guide defining a first airflow path and a second airflowpath; a first passage configured to direct the first airflow path to thefirst cooling chamber; a second passage configured to direct the secondairflow path to the second cooling chamber; a first tangential onboardinjector (TOBI) disposed in the first airflow path; and a second TOBIdisposed in the second airflow path, wherein the first TOBI is disposedradially outward from the second TOBI, and the first cooling chamber isdisposed forward from the second cooling chamber.
 9. The engine sectionof claim 8, wherein the first passage includes a first inlet defined inan axially forward surface of the disk, the first TOBI configured todirect the first airflow path into the first inlet.
 10. The enginesection of claim 9, wherein the second passage includes a second inletdefined in the axially forward surface of the disk, the second TOBIconfigured to direct the second airflow path into the second inlet. 11.The engine section of claim 8, wherein the first passage includes afirst inlet defined in an axially forward surface of a root, and whereinthe second passage includes a second inlet defined in the axiallyforward surface of the disk.
 12. The engine section of claim 8, furthercomprising a radial onboard injector (ROBI) disposed in the secondairflow path forward of the disk and configured to direct the secondairflow path radially inward.
 13. The engine section of claim 12,further comprising a minidisk coupled to an axially aft surface of thedisk, wherein the second airflow path is directed radially outwardbetween the minidisk and the axially aft surface of the disk.
 14. Theengine section of claim 8, wherein the blade defines a first pluralityof holes at a leading edge, and wherein the first airflow path isdirected out the blade through the first plurality of holes.
 15. A gasturbine engine, comprising: a compressor section configured to supplyairflow to at least one of a first airflow path or a second airflowpath; a turbine section configured to receive airflow from the firstairflow path and the second airflow path, the turbine sectioncomprising: a disk configured to rotate about an axis, a blade coupledto the disk, the blade defining a first cooling chamber and a secondcooling chamber, a first passage configured to direct a first airflowpath to the first cooling chamber; and a second passage configureddirect the second airflow path to the second cooling chamber; a firsttangential onboard injector (TOBI) disposed in the first airflow path;and a second TOBI disposed in the second airflow path, wherein the firstTOBI is disposed radially outward from the second TOBI, and the firstcooling chamber is disposed forward from the second cooling chamber. 16.The gas turbine engine of claim 15, further comprising: a first flowguide disposed upstream of the disk, the first flow guide defining thefirst airflow path and the second airflow path; and wherein the firstpassage includes a first inlet defined in an axially forward surface ofthe disk, the first TOBI configured to direct the first airflow pathinto the first inlet.
 17. The gas turbine engine of claim 16, whereinthe second passage includes a second inlet defined in the axiallyforward surface of the disk, the second TOBI configured to direct thesecond airflow path into the second inlet.